UC ANR teams with other universities, government agencies, non-profit organizations, landowners and California residents in the fight to prevent, eradicate or control invasive species.
The UC Integrated Pest Management Program and the Center for Invasive Species Research are two UC Agriculture and Natural Resources programs that monitor invasive species and coordinate responses when they become established in the state. They work closely with UC ANR advisors and specialists, government agencies and nonprofit organizations on eradication, management and prevention of these threats.
At an invasive species summit last year in Sacramento, UC ANR vice president Glenda Humiston and California Department of Food and Agriculture secretary Karen Ross convened scientists, government representatives and volunteers to pool intellectual resources and plot a strategy for protecting agricultural crops, natural resources, cityscapes and residential neighborhoods from invasive species.
“We know that collectively, we have the tools and expertise to prevent invasive species from entering California, spreading and becoming established,” Humiston said.
Below are three examples of pests that entered California, and with research, collaboration and treatment, were eradicated from the state.
European grapevine moth
European grapevine moth, a native of Mediterranean Europe, was detected for the first time in the Americas in Chile in April 2008. The following year, European grapevine moth was found in California's iconic wine region, Napa Valley. From there it spread to nine other California counties, as far south as Fresno. UC ANR academics responded rapidly — working with public and private partners and international scientists — to develop a pest management program that relied on deploying pheromone dispensers to disrupt mating and application of carefully timed insecticides. UC ANR academics studied the moth's biology, life cycle, host range and proven management practices. In short order, the moth population plummeted, and eventually the state was declared free of European grapevine moth, lifting a quarantine, enhancing farmers' ability to export their agricultural products, and preserving the communities' economic wellbeing. More info: Growers, scientists and regulators collaborate on European grapevine moth program
European grapevine moth
Pink bollworm of cotton
It took 50 years, but the invasive pink bollworm of cotton was declared eradicated in California in 2018. Eradication of pink bollworm was a joint effort by UC Cooperative Extension, USDA's Agricultural Research Service, county agricultural commissioners' offices and California cotton growers. It involved the implementation of integrated pest management techniques, such as planting transgenic cotton, using insect pheromones to disrupt mating, releasing sterile insects to slow reproduction, plowing after each crop to provide host-free periods, and extensive surveying. California cotton growers funded the program by paying an assessment on cotton grown in the state. More info: Pink bollworm UC Pest Management Guidelines
Pink bollworm larvae
Red palm weevil
In August 2010, arborists removed a dying Canary Island date palm from the yard of a Laguna Beach home and reported finding large black and red striped beetles. The pests were confirmed to be the first record of the destructive red palm weevil in the U.S. Hormone monitoring and visual surveys of other palms in the area confirmed the presence of the pest. Rapid action was taken against the pest by applying pesticides to trees that showed feeding damage to palm fronds. Effective surveying was accomplished by combining hormone attractants and cut pieces of palm trees provided by the California date palm industry. The last live weevil was detected in Laguna in January 2012. After three years passed with no weevil detections in Laguna Beach, USDA-APHIS declared this pest to be officially eradicated in January 2015. More info: Red palm weevil successfully eradicated form California
A symptom of HLB in citrus is the yellowing of leaves on an individual limb or in one sector of a tree's canopy. (Photo: Citrus Pest and Disease Prevention Program)
Huanglongbing (HLB) is a devastating bacterial disease of citrus that is starting to spread rapidly in urban areas of Southern California. The disease is spread by the invasive insect Asian citrus psyllid.
Asian citrus psyllid was first identified in California in 2008, and has been found from San Diego and Imperial counties in the south, all the way to Sacramento County in the north. See a map of Asian citrus psyllid and huanglongbing distribution in California.
UC Agriculture and Natural Resources specialists and advisors are working with the citrus industry, USDA and CDFA to control ACP populations and keep HLB contained while researchers search for a cure for the disease.
In order to find and remove infected trees before ACP can spread the disease to other trees, UC scientists are focusing research on early HLB detection technologies (EDTs). When infections first start, the bacteria are in just a few leaves. If the sampler doesn't collect those leaves, the disease can be missed. It can take one to two years for the bacteria to distribute itself throughout the tree so this sampling error doesn't occur.
Early detection technologies use whole tree responses to early infections. For example, Carolyn Slupsky, food science and technology professor at UC Davis, measures changes in tree metabolism (its day-to-day chemical function) when it becomes infected. Every leaf on the tree is connected to the tree's metabolism, so it doesn't matter which leaf is collected. This type of test can detect an infected tree within weeks or months after infection instead of years.
Scientists are also studying ways to modify ACP so the insects are unable to spread HLB, and studying the use of conventional breeding, genome editing or genetic engineering to develop disease-resistant citrus. Read summaries of the research here.
Young Asian citrus psyllids, called nymphs, produce a white, waxy substance.
Keeping Asian citrus psyllid and huanglongbing disease at bay depends in large part on the active involvement of commercial citrus growers and California residents who have citrus trees in their home landscapes. The UC ANR Asian Citrus Psyllid Distribution and Management website provides detailed guidelines for growers and residents to monitor for Asian citrus psyllid and huanglongbing, and learn about options for reducing psyllid populations and responding to the disease if it's in your area.
View a four-minute video that shows how to monitor for ACP presence in residential citrus:
Below is a an article released by the US Forest Service Rocky Mountain Research Station. It is worth a read by anyone interested in rangelands and open space and the impacts from urban development. Especially chilling for Californians!
Homes on the Range: Helping to Understand Residential Development of U.S. Rangelands
Rangelands on the Edge quantifies and maps aspects of rangeland conversion, including watershed fragmentation. The darkest red color on the map represents the most fragmented rangeland watersheds.
When the words to the classic folk song “Home on the Range” were written in 1872, U.S.rangelands were much more extensive than they are today. Over the past three centuries in the coterminous United States, one-thirdofrangelands — once covering a billion acres — have been modified or converted to other land uses. This shift is projected to continue, because privatelyownedrangelands, which are the most likely to be converted to other uses, represent more than 60 percent ofAmerica'srangelands.
Residential Development and Spatial Analysis
Residential development has had a particularly significant impact on rangeland ecosystems, including wildlife habitat reduction and fragmentation, altered hydrology and water quality, and decreased availability of natural and recreational goods and services. It's a growing issue, as an additional 5.6 million acres of U.S. rangelands are expected to make way for residential development in the next two decades or so, with more than 1 million of those acres in California and Texas alone.
To better understand where and how residential development is likely to affect U.S. rangelands, a team of scientists is collaborating on an ongoing project known as Rangelands on the Edge, which estimates past and projected rangeland conversion while evaluating landscape-level rangeland threats. It's similar to another Forest Service project called Forests on the Edge, which also has the key goals of increasing awareness of ecosystem values and challenges while creating tools for strategic planning.
Much of the decline in rangeland area is due to land use changes associated with exurban development, agriculture, and grazing (Photo by Carrie MacLaren, courtesy of 1000 Friends of Oregon).
According to the spatial analysis described in the report, continued rangeland conversion will affect some areas more than others. California and Texas are likely to be most affected, followed by Florida, Arizona, and Colorado. States with less dense human populations, such as Wyoming, Montana, and North Dakota, will be impacted less although localized changes may be significant. Also, further rangeland conversion is most likely around urban areas. The report also indicates that residential development impacts are reduced by concentrating housing in specific areas while setting aside and managing open spaces through conservation easements and land purchases.
Through a project called Rangelands on the Edge, RMRS scientists and collaborators are studying past, current, and projected changes to rangelands related to residential development in the conterminous United States.
A recently published report on the project includes maps and analysis of variables such as housing density, road and soil characteristics, topography, proximity to population centers, and land cover, use, and ownership.
This information can help refine planning and development decisions related to residential locations, land cover, highway placement, watershed management, and minimizing the effects of rangeland fragmentation.
While past U.S. rangeland conversion has been driven by agricultural development, especially in the Great Plains region, the greatest projected residential development is in the arid Southwest and California, especially near urban areas. Of more than 5.3 million acres of projected residential development through 2030, nearly 2.5 million acres are in California and Texas. Certain smaller urban centers such as Bozeman, Montana, will also continue to experience rapid changes.
Scientists are available to help interpret findings on a local level. Additional information can be obtained by contacting Matt Reeves at email@example.com.
Planning for Wildfire, Wildlife Management, and More
Reeves also describes an issue he's seen in western Montana: “Here in the Bitterroot Valley, the human population is expanding while agricultural and rangeland resources are being diminished. As a result, there's been an increase in motor vehicle collisions with elk as they're squeezed into corridors that might require them to cross a road. Our research can help develop travel management plans that consider wildlife corridors and include carefully placed overpasses, underpasses or fences.”
Reeves hopes the work will enable more informed decision-making related to U.S. rangeland development. He explains, “While there's some urgency about this issue, there's also opportunity. We believe that this research is the first step in more localized research, which will help bring people to the table.”
Mark your calendar!
July 15, 2019
The 3rd Annual UAV/Ag Technology Field Day
Presented by UC Cooperative Extension, Merced County
9am to 11:30am (CE registration begins at 8:30am)
Bowles Farming Headquarters
Scientific evidence of a warming climate in California and across the globe is clear, but the impacts on ecosystems and agriculture are still difficult to predict.
Sophisticated computer models are used to forecast future climate. Understanding that temperature and precipitation levels will change in the future does not tell the full story: UC Agriculture and Natural Resources researchers also want real-world experience under those future conditions.
Moreover, some agricultural operations have higher sensitivity to the changes than others. Rangeland forage is particularly sensitive to climate changes since, unlike irrigated agriculture, ranchers rely solely on precipitation. They have no control over how much and when it rains.
SFREC director Jeremy James stands next to a small chamber designed to simulate effects of warming air and soil temperatures on rangeland grasses. The poly carbonate hexagons slow rates of heat loss from plots, allowing scientists to artificially warm plants and soils in the chambers. (Photo: Linda Forbes)
Discovering climate change impact on rangeland
In order to study different climate projections on rangeland, James and Maggi Kelly, director of the UC ANR Informatics and Global Information Systems special program, have begun development of a research site that will allow scientists to manipulate the temperature and rainfall on sections of rangeland to understand what would happen under predicted weather scenarios.
The new research facility is currently under construction. (Photo: Linda Forbes)
With a $220,000 National Science Foundation grant, construction is now underway on a four-acre site at the research center that will help scientists learn how temperature and precipitation will impact growth and diversity of forage that ranchers use to raise their livestock.
“We need to know how rangelands will respond when conditions change,” James said. “Will we grow more, but dry out earlier? Will we have more medusahead (an undesirable rangeland weed) or more soft chess (a high quality forage)?”
When complete, 16 shelters on steel tracks will be connected to computer systems and hydraulic motors to move them up or down a research plot. The shelters and other equipment will allow scientists to precisely control the amount of precipitation (or irrigation water) that rains onto the plot. Other systems will give researchers control of air temperature.
“This facility isn't designed for one type of research,” James said. “It is designed to conduct a wide variety of research by scientists over the next several decades. With this setup, we can look at the effect of climate change on soil biological communities, soil carbon, insect communities, plant-insect interactions and oak seedling recruitment.”
The research results from the project should provide ranchers and land managers a better understanding of how climate change may impact agriculture and ecosystem function on rangeland while also providing important information on how to minimize impacts of these changes.
Some aspects of the research facility's development are not covered with funding from the National Science Foundation. The scientists are looking for additional support to complete the project.
The Sierra Foothill Research and Extension Center is one of nine centers across the state of California UC Agriculture and Natural Resources manages for applied research.
Current work underway at the Sierra Foothill Research and Extension Center
The Sierra Foothill REC, a 5,000-acre facility on the Yuba River, has supported research, education and outreach in the Sierra foothills since 1960. Multiple lines of research are being conducted at SFREC. During a recent workshop, scientists from UC Davis, UC Berkeley and UC Cooperative Extension shared a sampling of their work at SFREC.
UCCE livestock and natural resources advisor Dan Macon described a project aimed at helping ranchers make decisions about maintaining a cattle herd when faced with impending drought. Ranchers are reluctant to sell off their cattle even when the near future weather forecast is dire.
“Science tells us you shouldn't feed your way out of a drought,” Macon said. “But you want everything to stay the same. You want to maintain your genetic potential and keep cows that are familiar with the area.”
Working with ranchers, the research project will compare management practices to determine the best way forward when the future looks meteorologically bleak.
“We're assigning cows to a traditional weaning and early weaning groups,” Macon said. “They'll be out on the range from March to early September under different parameters. We're also tying in economics, the value of genetic potential and the value of having cows who know the landscape.”
UCCE advisor Dan Macon, far left with cap, speaks to participants at the workshop.
Research by University of Oregon post doctorate researcher Ashley Shaw is looking into whether compost applied to rangeland will help mitigate climate change by sequestering more carbon, and also benefit forage under drought by increasing the soil's water-holding capacity and improving nutrient delivery.
Preliminary results are promising. A single application of 1/4-inch of compost resulted in forage production that was higher than areas where no amendment was applied and areas that were treated with a chemical fertilizer.
“The biggest impact was under drought shelters,” said Shaw, referring to PVC frames that were covered with plastic during rain events to understand the impact of the treatment under dry conditions. “In the drought plots, the areas where compost was applied are staying green longer.”
A review of the data shows surprising variations and correlations at the center, where forage production averages 3,000 pounds per acre, but ranges from about 1,000 pounds per acre in 1987, to over 5,000 pounds per acre in 2018, when there was so much growth, “we didn't have enough animals to graze,” James said.
The dataset paints a spectrum of the variation that ranchers across the state must navigate to manage their livestock and rangeland in a way that is profitable and ecologically sound. Research at the Sierra Foothill REC offers invaluable information to help them better understand the ecosystem and make informed decisions.